docs: more data for comparisions

docs/area.or.point.md

@@ -15,9 +15,9 @@ When a geotiff is `Pixel Is Point` the tiff's origin point is shifted by half a
 
 LINZ elevation DEM and DSM's current contain a mixture of `Point` and `Area`
 
-From a [brief survey of other jurisdictions](./national.dem.dsm.comparision.md) they all use `Area`,
+From a [brief survey of other jurisdictions](./national-dem-dsm/README.md.md) they mostly all use `Area`,
 
-Area is also consistent with how aerial imagery is stored.
+Area is also consistent with how [LINZ's aerial imagery](https://github.com/linz/imagery) is stored.
 
 ## References
 

docs/national-dem-dsm/README.md

@@ -0,0 +1,33 @@
+# Other countries DEM/DSM publication
+
+Before making recommendations on how to standardise New Zealand's DEM/DSM data LINZ took a brief look at other jurisdictions and how they standardised their DEM and DSM
+
+The key areas to look at were
+
+- compression - What lossless compression was most common
+- size - width and height of image
+- file size - how big each tile is
+- storage type (Tiff/COG/other)
+
+| Country     | Name                                                                                                         |       Dimensions        | File SIze | Type          | Compression      | DataType | Nodata  | CRS        | PixelIsPoint | Comments |
+| :---------- | :----------------------------------------------------------------------------------------------------------- | :---------------------: | --------- | ------------- | ---------------- | -------- | ------- | ---------- | ------------ | -------- |
+| New Zealand | [National Elevation 1m DEM](https://data.linz.govt.nz/group/national-elevation/data/)                        |       480x720 px        | 1.4MB     | GeoTiff       | LZW              | Float32  | -9999   | EPSG:2193  | Area/Point   |          |
+| Switzerland | [swissSURFACE3D Raster (50cm)](https://www.swisstopo.admin.ch/en/geodata/height/surface3d-raster.html)       |     2,000x2,000 px      | 16MB      | GeoTiff (COG) | LZW              | Float32  | -9999   | EPSG:2056  | Area         |          |
+| USA - USGS  | [National Map 3DEP](http://prd-tnm.s3.amazonaws.com/index.html?prefix=StagedProducts/Elevation/1m/Projects/) |    10,012x10,012 px     | 280MB     | GeoTiff (COG) | LZW (predictor3) | Float32  | -999999 | EPSG:26910 | Area         |          |
+| USA - NOAA  | [NOAA Digital Coast LiDAR](https://coast.noaa.gov/dataviewer/#/lidar/search/)                                |     8,463x6,475 px      | 189NB     | GeoTiff       | LZW              | Float32  | -999999 | EPSG:2229  |              | In Feet  |
+| Australia   | [Victoria 50cm DEM](https://elevation.fsdf.org.au/)                                                          | 10,000x10,000<br>Varies | 4MB       | GeoTiff (COG) | LZW              | Float32  | -9999   | EPSG:7855  |              |          |
+| Finland     | [2M DEM](https://asiointi.maanmittauslaitos.fi/karttapaikka/tilausvahvistus)                                 |     3,000x3,000 px      | 20MB      | GeoTiff       | LZW              | Float32  | -9999   | EPSG:3067  |              |          |
+| Canada      | [HRDEM - CanElevation Series](https://open.canada.ca/data/en/dataset/957782bf-847c-4644-a757-e383c0057995)   |      10,000x10,000      |           | GeoTiff       | LZW              | Float32  | -32767  | EPSG:2958  |              |          |
+| Norway      | [Norway DTM1](https://hoydedata.no/LaserInnsyn2/)                                                            |      15,010x15,010      |           | GeoTiff       | LZW              |          |         |            |              |          |
+| France      | [RGE ALTI 1m](https://geoservices.ign.fr/rgealti)                                                            |       1,000x1,000       |           | Ascii Grid    |                  |          |         |            |              |          |
+| Netherlands | [Actueel Hoogtebestand Nederland AHN3](https://app.pdok.nl/rws/ahn3/download-page/)                          |      10,000x12,500      |           | GeoTiff       | RAW (Zipped)     |          | 3.4e+38 | EPSG:28992 |              |          |
+| Scotland    | [LiDAR for Scotland DTM](https://remotesensingdata.gov.scot/data#/list)                                      |      10,000x6,000       | 132MB     | GeoTiff       | LZW              |          | -9999   | EPSG:27700 | Area         |          |
+|             |                                                                                                              |                         |           |               |                  |          |         |            |              |          |
+
+​Elvis - Elevation and Depth - Foundation Spatial Data
+
+https://asiointi.maanmittauslaitos.fi/karttapaikka/tilausvahvistus
+
+File Tested
+
+Scotland - NN70_1M_DSM_PHASE1.tif